Universal excavator



July-27, 1965 F. scHwlNG 3,197,049

UNIVERSAL EXCAVATOR Filed April 30. 1964 I 3 Sheets-Sheet 1 INVENTOR. FRIEDRICH SCHWING ATTORNEYS July 27, 1965 F. SCHWING UNIVERSAL EXCAVATOR 3 Sheets-Sheet 2 Filed April 30. 1964 N .mw

INVENTOR. FRIEDRICH SCHWING ATTORNEYS July 27, 1965 Filed April 30. 1964 F. SCHWING UNIVERSAL EXGAVATOR WE TM 3 SheetsfSheet 3 INVENTOR. FRIEDRICH SCHWING ATTORNEYS United States Patent O 3,197,049 UNIVERSAL EXCAVATOR Friedrich Sehwing, Dorstenerstrasse 441, Wanne-Eickel, Germany Filed Apr. 3G, 1964, Ser. No. 363,797 Claims priority, application Germany, May 2, 1963,

Seh 33,222 3 Claims. (Ci. 214-138) The invention relates to a universal excavator or a similar device which automatically achieves straight-line travel of the tools attached thereto in any position or direction.

With standard `dipper shovels, the dipper stick describes a circle about a .pivot point at the associated boom. Accordingly, the tool attached to the dippe-r stick also assumes circular motion. Therefore, the path of the tool is a circular are, when the clipper stick moves around the pivot .point at the looom.

If the boom, Which carries the block of the dippcr stick is moved in a vertical direction about its pivot point at the shovels revolving frame, the tool makes another motion. lf now the speeds of these motions, as a function of the path traveled by the tool, are controlled, it is possible to produce a straight-line motion of the tool. This is also possible, if one motion is carried through at a constant speed and if the other motion is regulated in its speed. If, -in addition, the cutting angle of the tool is to be kept constant during the straight-line travel, it is necessary in addition to swing the tool at an exactly controlled angular velocity at the dipper stick. From these basic considerations, it results that in case of standard dipper shovels an unusual effort on the `part of the machine as well as physically on the par-t of the operator is necessary to achieve a straight-line travel under any single angle.

Accordingly, any other straight-line travel than that under the above mentioned angle again would require a specic control procedure. It is easily imaginable that even in a case, where the working motion (travel) can be carried through very slowly and with great accuracy, the accuracy of the work decisively wou-ld depend on the operators reaction and measuring by sight. Therefore, the working speed has to be especially low to give the operator time to react so he can cor-rect an operating error, if he has recognized it and to avoid a too great deviation of the tool from the specified path during this time.

Excavators are known, which seem to be better suited to accomplishing straight-line travels than the above discussed dipper shovels of standard design. With such machines, the tool is attached to -a stick, which is guided by rollers coaxially arranged to this stick and carrying the tool at its front end. It is possible to produce a straight travel of the tool by shorteningr or lengthening this systern.

But this working equipment consisting of the two coaxial stick parts and the tool attached to them has the grave disadvantage that even in a totally retracted state it still has such a length that the pivotal point of the working equipment must :be arranged at the revolving frame lin a very high position in order that the working equipment `can be swung upwards -in the vertical direction by a possibly wide angle over the horizontal position without bumping with the retracted stick part projecting over the block into the shovels cab. By shifting the block towards the end of the working equipment, the part prjecting over the block could be shortened by any length. But the position of the pivot point, with regard to the yrevolving fra-me and truck frame of the shovel, depends on the fact that in case, where the excavator crowds under its floor level, i.e. where the boom is lowered by approxi- ICC mately 45 in vertical direction to the horizontal level, the revolving frame can be rotated around its vertical axis :without the danger thatl the working equipment collides with the truck frame. Moreover, the pivotal point must be mounted at such a height that the tool in retracted state -of the working equipment reaches the ground level.

By setting back the pivotal point in relation to the working equipment, tne machines Working angle consequently would increase and the position of the pivotal point would have to be moved upwards without increasing the possible travel of the tool.

When observing the necessary stability of the machine, the machines own weight in relation to the travel of the tool would increase in such an unfavorable proportion that because of reasons of economy this way is not followed.

This is the reason why with such an excavator, for example, no horizontal soil sub-grade at the height of shovels level can be produced in such a simple manner that after adjustment of the direction only that part of the hoorn is retracted or crowded, which carries the tool. llt rather requires a simultaneous downward or upward swinging of the working equipment at an angular velocity, which -rnust be controlled in a very certain manner, namely as a function of the tools travel. rIherefore, with this type of machine the accuracy or" the working motion depends on the skill of the operator.

With machines of a diferent design the tool, like a trolley, is guided in straight direction with the assistance of rol-1ers at a stick. This system has not all the disadvantages o-f the one mentioned above. Without difficulties it can be so hinged at the revolving h'ame that straight-line travels of the tool can be carried through in any direction by swinging the Work equipment including the rail and tool -in vertical direction.

But the greatest disadvantage of this system lies in the fact that in case of a partially or entirely retracted tool, the frontward projecting part of the boom serving as guide to trace a straight line makes it impossible to carry through many operations. Thus, when Working on a steep slope with low depth below the shovels level, for example when working on a trench, the projecting end `can collide with the bottom of the trench or the opposite wa-ll :of 4the trench before the tool has touched the bottom. Therefore, this type of machine can be used only -for special jobs, -for example smoothing of already rather precisely pre-worked slopes of tting length.

rihe decisive disadvantage of the two last discussed types of excavators thus lies in the great length of the equipment, which even in case 'of a totally retracted tool is greater than the maximum straight travel of the tool achieved with the help of the equipment.

The present invention intends to remove this shortcoming; namely, in so far that for the automatically straight-line motion of the tool, n'o rails or similar elements are employed. Rather, such systems, which consist of hinged mem-bers which collapse when the too-l is retracted to the individua-l length of the working equipment always is as large as the remaining travel of the tool.

Many systems are conceivable for straight-line motion without use of rails, etc. It is, for example, possible to design a system consisting of two partsdthe Iboom and the dipper stick with the tool-through the correct selection of lever lengths and angles in such a way that the cutting edge of the Itool automatically follows a sufliciently accurate straight-line motion, if only the two hydraulic cylinders, which effect the rotating motions of the Vdipper stick in relation to the boom or of the boom in relation to the revolving frame, always are operated through an independently constant oi-l delivery ow of an appropriate volume.

Moreover, systems are conceivable in which the hydraulic cylinders serve only as drive and are not at the same time to achieve lthe straight-line motion, as well as such systems, where instead of hydraulic cylinder motors, gear racks or hoistsI are used.

The inve-ntion overcomes the above mentioned disadvantages and at the same time achieves many advantages. In its broadest embodiment, lthe invention is capab-le of automatically effecting straight line travel of a shovelth-rou gh the folding of a system of hinged mem- Ibers, the length of travel of which is longer than the length of the folded system. f

Other objects and advantages of the i-nve-ntion will become apparent from reading the following detailed descriptionr of an embodiment thereof considered in the light of the attached drawings, in which:

FIG. 1 is an elevational view of a universal excavator incorporating the novel features of the invention, where the Working level is below the shovels level. The dotted lines indicate the machines position after the bucket has completed its travel across the surface being shoveled.

FIG. 2 is an elevational view similar to FIG. 1 showing the same excavator with an elevated base of the Working surface with the boom swung to the lowest position. The dotted lines indicate the working system raised upwardly; and

FIG. 3 is an elevational View similar to FIGS. l and 2 showing `an elevated Working surface. In tins case the working level of ythe tool lies above the shovels ground level.

Referring to the drawings, the working system consists of a tool or bucket member 1 pivotally mounted at E on one end of a front arm or dipper stick 3. A hydraulic cylinder Zhas one end pivotally mounted at F to the bucket 1 in spaced relation from the point E. The other end of the hydraulic cylinder 2 and a point spaced from the other end of the front arm 3 are pivotally connected in spaced relation between a pair of center crank arms 4 at pointsG and H, respectively.

A rear arm 5 is pivotally connected at a point spaced from one of its ends between the opposite end of the crank arms 4 at a point C; while the other end of the rear arm 5 is pivotally connected to the center point of another crank arm 11 as at A. Further, there is provided guide rods or linkagesl 6, one end of which is pivotally connected to anV intermediate point D of the crank arm 4; `while the other ends of the linkages 6 are pivotally connected to the one end of the crank arms '11 at B.

A working or yoperating hydraulic cylinder 7 has one end thereof pivotally connected to a-bracket depending from an intermediateportion of the rear arm S; while the other end is pivotally connected between the crank members 11 at point B.

The crank members 11 are pivotally connected to the extended end of an auxiliary boom 9 at point A. The opposite end of the boom 9 is pivotally connected to a pair of spaced linkages 12 and 13. The opposite ends of the linkagesy 12 and i3 are pivotally connected to an upwardly extending member llt which is integrally connected to the main frame of the excavator vehicle. The pivot points of the linkages l2 and i3 on the boom 9 are substantially equidistantly spaced with respect to the pivot points of the linkages on the member i4. Ahydraulic hoist ram Sis pivotally mounted between a bracket connected -to the auxiliary boom 9 and one end of the crank member 11.

A boomadjusting hydraulic cylinder 16 has its opposite ends pivotally mounted on a bracket depending from the intermediate portion of the linkage 13 and a downwardly positioned point on the member 14.

It will be manifest that the rear arm 5 forms one side of a parallelogram, while the linkage 6 forms the opposite side. The other sides ofthe parallelogram are formed by that portion of the center crank arm 4 between the pivot points C and D, and that portion of the other crank arm El between the pivot points A and B. lt will be understood that when the operating cylinder 7 is energized to effect any position of the auxiliary boom the line CD will remain parallel to the line AB, as illustrated in the various FlGS. l through. 3. Consequently, the center crank arm 4 will, at all times during straight line working motion, remain parallel to itself.

The front arm 3 and the rear arm 5 pivotally connected to the center crank arms 4 are coupled together by crossing chains, which are a substitute for a gear-'tooth system. This coupling insures that the arms 3 and 5, in the case of the straight-line working motion relative to the center arm 4, have an angular velocity which is at all times constant, but reversely directed.

It will be observed that the above described mechanism is illustrated as being applied to a mobile truck mounted trencher or backhoe. However, it is not desired to limit the invention to use in conjunction with such a device, inasmuch as with certain modications, it may be applied to other types of excavating apparatus.

By energizing the operating hydraulic cylinder 7, the pivot point E of the associated bucket l automatically moves on the straight line between points A and E.

Since the points E, F, A and H form a parallelograrn, the bucket 1 remains in a constant attitude as it is moved through its working cycle toward the supporting vehicle frame. Accordingly, the cutting cycle of the bucket l also remains constant. The line AB and thus the apparatus attached thereto can be lifted vertically by the hoist ram 8. This is required when it is desired to work on an elevated working surface such as illustrated in PEG. 3. Moreover, as the auxiliary boom 9 can be adjusted toany desired height through the energization of the hydraulic cylinder 1t?, it will be seen that the bucket 1 and associated mechanism can be moved to perform the desired operation at any height. Also, through the cooperative effort of the cylinders 8 and 10, the bucket 1 can be positioned to perform its straight line work along anyangle with respect to the horizontal.

By supplying the working cylinder 7 with a constant delivery tlow of oil and the cylinder S with a precisely regulated delivery ow of oil, any working motion of the bucket in deviation from the automatic straight-line motion can be accomplished.

In order to effect pivotal movement of the bucket 1 about the axis illustrated by the line K-K, hydraulically actuated cylinders 15 are provided.

In accordance with the provisions of the patentstatutes, I have illustrated and described what l now consider to e the preferred embodhnents of the invention. However, I desire to have it understood that the invention may be practiced otherwise than illustrated and described within the scope of the appended claims.

What I claim is:

1. In an excavating apparatus, the combination with a movable support of:

a front dipper stick;

a bucket pivotally connected at its open end to said dipper stick at one end thereof;

Y lirst hydraulic means pivotally connected adjacent one end, to said bucket at a point spaced from the end of said dipper stick;

a first crank arm, the other end of said dipper stick pivotally connected to said arm intermediate the ends thereof, the opposite end of said first hydraulic means pivotally connected to one end of said arm, `the distance between the pivotal connections of the one end of said front dipper stick and said rst hydraulic means to said bucket being substantially equal to the distance between the pivotal connec tions between the other ends of said front dipper stick and said rst hydraulic means to said lirst crank arm;

a rear arm pivotally connected adjacent one end to the other end of said lirst crank arm;

linkage means pivotally connected adjacent one end to said rst crank arm at a point between the pivotal connections of said front clipper stick and said rear arm thereto;

a second crank arm, the other end of said rear arm pivotally connected to the second crank arrn ntermediate the ends thereof, the opposite end of said linkage means pivotally connected to one end of said second crank arm, the distance between the pivotal connections of the one end of said rear arm and said linkage means to said rst crank arm being substantially equal to the distance between the pivotal connection between the other ends of said rear arm and said linkage means to said second crank arm;

a hydraulic work cylinder pivotally connected between the one end of said second crank arm and a point intermediate the ends of said rear arm;

an auxiliary boom having one end mounted for selected vertical movement on said movable support, the

other end of said boom pivotally connected to said second crank arm at a point intermediate the ends thereof; and second hydraulic means pivotally connected adjacent v5 one end to the other end of said second crank arm and the other end to a point on said boom.

2. The invention delined in claim 1 wherein the other end of said front clipper stick and the one end of said rear arm are coupled together by crossing chain means.

3. The invention defined in claim 1 including means for effecting pivotal movement of said bucket about an axis in a plane substantially perpendicular to the plane of the axes of the pivotal connections of said bucket to said first hydraulic means and said front dipper stick.

15 References Cited by the Examiner UNITED STATES PATENTS 3,080,076 3/63 Randall 214-138 20 HUGO O. SCHULZ, Primary Examiner. 

1. IN AN EXCAVATING APPARATUS, THE COMBINATION WITH AW MOVABLE SUPPORT OF: A FRONT DIPPER STICK; A BUCKET PIVOTALLY CONNECTED AT ITS OPEN END TO SAID DIPPER STICK AT ONE END THEREOF; FIRST HYDRAULIC MEANS PIVOTALLY CONNECTED ADJACENT ONE END TO SAID BUCKET AT A POINT SPACED FROM THE END OF SAID DIPPER STICK; A FIRST CRANK ARM, THE OTHER END OF SAID DIPPER STICK PIVOTALLY CONNECTED TO SAID ARM INTERMEDIATE THE ENDS THEREOF, THE OPPOSITE END OF SAID FIRST HYDRAULIC MEANS PIVOTALLY CONNECTED TO ONE END OF SAID ARM, THE DISTANCE BETWEEN THE PIVOTAL CONNECTIONS OF THE ONE END OF SAID FRONT DIPPER STICK AND SAID FIRST HYDRAULIC MEANS TO SAID BUCKET BEING SUBSTANTIALLY EQUAL TO THE DISTANCE BETWEEN THE PIVOTAL CONNECTIONS BETWEEN THE OTHER ENDS OF SAID FRONT DIPPER STICK AND SAID FIRST HYDRAULIC MEANS TO SAID FIRST CRANK ARM; A REAR ARM PIVOTALLY CONNECTED ADJACENT ONE END TO THE OTHER END OF SAID FRIST CRANK ARM; LINKAGE MEANS PIVOTALLY CONNECTED ADJACENT ONE END TO SAID FIRST CRANK ARM AT A POINT BETWEEN THE PIVOTAL CONNECTIONS OF SAID FRONT DIPPER STICK AND SAID REAR ARM THERETO; A SECOND CRANK ARM, THE OTHER END OF SAID REAR ARM PIVOTALLY CONNECTED TO THE SECOND CRANK ARM INTERMEDIATE THE ENDS THEREOF, THE OPPOSITE END OF SAID LINKAGE MEANS PIVOTALLY CONNECTED TO ONE END OF SAID SECOND CRANK ARM, THE DISTANCE BETWEEN THE PIVOTAL CONNECTIONS OF THE ONE END OF SAID REAR ARM AND SAID LINKAGE MEANS TO SAID FIRST CRANK ARM BEING SUBSTANTIALLY EQUAL TO THE DISTANCE BETWEEN THE PIVOTAL CONNECTION BETWEEN THE OTHER ENDS OF SAID REAR ARM AND SAID LINKAGE MEANS TO SAID SECOND CRANK ARM; A HYDRAULIC WORK CYLINDER PIVOTALLY CONNECTED BETWEEN THE ONE END OF SAID SECOND CRANK ARM AND A POINT INTERMEDIATE THE ENDS OF SAID REAR ARM; AN AUXILIARY BOOM HAVING ONE END MOUNTED FOR SELECTED VERTICAL MOVEMENT ON SAID MOVABLE SUPPORT, THE OTHER END OF SAID BOOM PIVOTALLY CONNECTED TO SAID SECOND CRANK ARM AT A POINT INTERMEDIATE THE ENDS THEREOF; AND SECOND HYDRAULIC MEANS PIVOTALLY CONNECTED ADJACENT ONE END TO THE OTHER END OF SAID SECOND CRANK ARM AND THE OTHER END TO A POINT ON SAID BOOM. 